Aluminum alloy



Patented Nov. 18, 1930 UNITED STATES PATENT .OFFICE HORACE CAMPBELL HALL AND TENNYSON FRASER; BRADBUBY, O F DERBY, ENGLAND, ASSIG NORS TO ROLLS-ROYCE LIMITED, 01 DERBY, ENGLAND ALUMINUM ALLOY No Drawing. Application filed October 23, 1929, Serial No. 401,970, and in Great Britain December 18, 1928.

The object of this invention is to make an aluminum alloy having certain properties superior to those of any aluminum alloys heretofore known.

It is common knowledge that aluminum alloys often undergo an appreciable decrease in strength and hardness when subjected to an increase of temperature. ,In aluminum alloys where an improvement in character istics takes place by heat treatment it is frequently found that an impairment of the characteristics takes place when the alloy is subsequently heated to a moderate temperature, althoughin some cases and under some conditions, the deterioration is reduced or the former condition restored on'a return to normal temperature. Our invention has for its object to overcome or reduce the disadvantages and deterioration before mentioned.

An alloy made accordmg to this lnvention is one improved by heat treatment, and which is afi'ectedto a very small extentby subsequent heating to a moderate temperature.

According to this invention we make an alloy by compounding the elements, and that in relative quantities within the ranges set out below :copper 0.5 to 5.0 per cent of the whole, magnesium 0.1 to 1.7 per cent of the whole, nickel 0.2 to 1.5 per cent of the whole, iron 0.6 to 1.5 per cent'of the. whole, silicon .55 to 2.8 per cent of the whole, titanium u p to .3 per cent'of the whole, manganese up to .3

. per cent of the whole, aluminum the remainder, only traces of other elements.

With an alloy compounded as above, a casting can be made which islight, strong, easily and satisfactorily cast and forged, gives good resistance to corrosion and posse'sses good mechanical qualities. Further the castings and forgings are susceptible to both high and low temperature in heat treatment to give improved mechanical properties.

Further, an alloy according to this invention is less susceptible to the harmful effects of vibration. and fatigue than are known alloys.

As an example of this alloy. with the maghardness are less affected 011 re-heating to about 300 C. than with known alloys and are restored on re-cooling.' Such an alloy would be verv suitable for such parts as piscommercial aluminum, we add aluminum alloys each rich in one or in some cases more than one of the required elements.

What we claim is An aluminum alloy formed by compounding the elements, and that in relative quantities respectively within the ranges set out below :copper 0.5 to 5.0 per cent of the whole, magnesium 0.1 to 1.7 per cent of the whole, nickel 0.2 to 1.5 per cent of the whole, iron 0.6 to 1.5 per cent of the whole, silicon .55 to 2.8 per cent of the whole, titanium up to .3 per cent of the whole, manganese up to .3 per cent of the whole, aluminum the remainder, only traces of other elements.

In testimony whereof we have aflixed our signatures.

HORACE CAMPBELL HALL.

TENNYSON FRASER BRADBURY. 

